An electronic key system for a vehicle is disclosed, for example, in Japanese Laid-Open Patent Publication No. 2001-349110 and Japanese Laid-Open Patent Publication No. 2001-349117. In the electronic key system for a vehicle disclosed in Japanese Laid-Open Patent Publication No. 2001-349110 and Japanese Laid-Open Patent Publication No. 2001-349117, starting means (switches) are provided on a door handle and a trunk lid of an actual vehicle. If a user operates (starts) any of the starting means, then communication of a control apparatus with an electronic key begins. Then, the control apparatus verifies an ID transmitted thereto from the electronic key with an ID registered therein. Thus, if it is verified that the IDs are coincident with each other, then the doors are unlocked and so forth.
Further, in Japanese Laid-Open Patent Publication No. 2001-349110 and Japanese Laid-Open Patent Publication No. 2001-349117 described above, a starting means (switch) is provided also on an ignition switch. If the user operates the ignition switch after the user gets on the four-wheeled car, then the communication between the electronic key and the starting means is performed again to perform ID verifying for permitting starting of the engine. Then, if it is verified that the IDs are coincident with each other, the engine is started.
In particular, in the conventional vehicle electronic key system for a four-wheeled car, the electronic key functions both to unlock a door and to permit starting of an engine.
Further, as a different prior art apparatus, an electronic key system is proposed (refer to, for example, Japanese Laid-Open Patent Publication No. 10-317754) wherein transmitting antennas are provided individually for doors of a four wheeled car, and only that one of the doors which is approached by a portable device can be unlocked independently of the other doors of the vehicle.
In this manner, in the electronic key system described above, the range of transmitting from the control apparatus mounted on an actual vehicle in the communication between the control apparatus and the electronic key is small in comparison with that from the electronic key. Therefore, in the prior art apparatus described above, a plurality of transmitting antennas for outputting a signal from the control apparatus are provided depending upon different applications.
Incidentally, in order to apply such an electronic key system to a motorcycle, at least when a user gets on and activates the vehicle and when the user operates the vehicle, it is necessary for the user to communicate with certainty with the electronic key carried by the user.
Particularly in a motorcycle such as a scooter wherein a helmet can be accommodated or stored in a space provided under a seat, it is necessary that the control apparatus communicates with the electronic key with certainty. This applies not only when the user gets on and operates the vehicle and when the user is traveling with the vehicle, but also upon opening or closing of the seat and when the electronic key is accommodated in the helmet storage space.
Particularly where the vehicle is a motorcycle of a large size, in order to achieve communication of the control apparatus with the electronic key in all of the situations described above, it is necessary to install a plurality of transmitting antennas at different locations such as a front portion and a rear portion of the actual vehicle. This may increase of the cost and the weight of the electronic key system and the installation space required for the electronic key system.
In a motorcycle such as a scooter wherein a helmet can be accommodated in a space provided under a seat, such a method as described below is available. In particular, a locking mechanism for locking an opening/closing mechanism of a seat is provided, for example, to prevent theft. Thus, if a legal user is recognized through communication of a control apparatus with an electronic key, then the seat is unlocked.
In such a case as just described, it is possible that an electronic key placed in a bag or the like is accommodated in a helmet storage space. In such a manner of use as just described, if communication between the control apparatus and the electronic key is interrupted, then there is the possibility that the seat cannot be unlocked, that is, shut-in of the baggage may occur.